This is something that's annoyed me through all the versions of windows, and with Windows 10, I'd hoped Microsoft had finally fixed it. They haven't. There is always only one resolution for the boot animation, but the three predominant display aspect ratios are 4:3, 16:9 and 16:10. Whenever there is a mismatch, you get a distorted boot animation. I've wondered if there wouldn't be a way to fix this, and googled up the information that people apparently edit "bootres.dll" with resource hacker like applications. The primary concern however is to infuse custom boot animations (e.g. that of a playstation booting), rather than to do something relatively simple such as changing the resolution. I've struggled to find any info on that. I hope it wouldn't mean to manually crop the Windows10 animation to be suitable for 4:3 displays (as is my case). Is there maybe someone here experienced with this? Many thanks